Fig. 5.

Muscimol-insensitive responses reflect amplitude and time course of monosynaptic thalamocortical input. A: pre- and postmuscimol (100 μM) current sinks evoked by tone stimuli spanning 2 octaves. B: group data showing current sink amplitudes in 5-ms intervals for layer 2/3 (top) and layer 4 (center) and in 2-ms intervals for layer 5/6 (bottom) (■, predrug; ○, postmuscimol). Note that timescale is identical for top and middle (5-ms intervals up to last 2 data points, which are 25–75 ms and 75–300 ms intervals) and different for bottom (2-ms intervals up to last 2 data points, which are 10–60 ms and 60–300 ms intervals). For each graph, response amplitudes are normalized to predrug peak value. Dark gray shading indicates strongest thalamocortical input, where amplitude in first 5-ms interval is not reduced by muscimol; light gray shading indicates significant reduction in first 5 ms; and no shading indicates complete reduction of response by muscimol.